A philosophical burlesque, Human Nature follows the ups and downs of an obsessive scientist, a female naturalist, and the man they discover, born and raised in the wild. As scientist Nathan trains the wild man, Puff, in the ways of the world - starting with table manners - Nathan's lover Lila fights to preserve the man's simian past, which represents a freedom enviable to most.

In a remote woodland cabin, a small town doctor discovers Nell — a beautiful young hermit woman with many secrets.